1. Field of the Invention.
The present invention pertains to a cooling device for an internal combustion engine disposed in an engine compartment of a motor vehicle, with a radiator positioned in front of the internal combustion engine and an axial-radial blower serving to feed cooling air through the radiator into the engine compartment.
2. Statement of the Related Art.
In a motor vehicle powered by an internal combustion engine with general state-of-the-art water cooling, a blower, which as a rule is formed as an axial blower, is mounted in front of or behind the cooling water radiator to support the engine cooling. The blower is actuated by an electric motor (e.g., in the case of a diagonally built-in internal combustion engine), but can also be actuated directly by the internal combustion engine (e.g., with flush fitting of same). Usually, a thermoswitch with a temperature detection device in the radiator serves to trigger the blower. The blower can also be triggered by a viscous fluid coupling reacting to the air temperature behind the radiator. However, based on the factors prevailing in the area of the engine compartment (mounted in the front) or the engine block of a motor vehicle, the air streamed through the radiator can no longer be additionally used to cool the engine compartment or the structure The air fed by the axial blower only touches the engine block. In the case of an adequate driving speed of the motor vehicle and the flow ratios caused thereby (relative wind), a vacuum is formed under the engine, which leads to a brisk downwards flowing away of the air fed through the blower. These pressure ratios on the engine block which are detrimental to the engine cooling are further increased by the front spoiler in common use today. Thus, in practice, the cooling air fed by the axial blower barely comes into contact with the engine block, by means of which the desired secondary cooling effect is substantially lost.
A cooling device of the type mentioned above is known from DE-AS No. 25 40 040. In this case, an axial-radial blower, in which the direction of the cooling stream is in front of a cooling water radiator designed as an annular radiator, is used to aerate and to cool the engine compartment. Thus, the annular radiator is on the pressure side of the blower, which intensely aggravates an air feed aimed to especially heated engine parts (such as the exhaust manifolds).
Furthermore, in the known cooling device, according to DE-AS No. 25 40 040, an engine compartment is provided that is completely closed up to an air input opening and an air output opening. In motor vehicles of conventional structure, particularly in cars, it is common to leave the engine compartment open toward the bottom or to compartmentalize it possibly partially by an engine compartment cover at a distance from the engine for reasons of noise. In such an engine compartment design, the cooling device according to DE-AS No. 25 40 040 would not be very effective, especially since the air exchange caused by the device with regard to the flow-through direction is more likely random and is only caused by the pressure differences between the air input opening and the output opening.
Additional disadvantages of the known cooling device according to DE-AS No. 25 40 040 are shown in that part of the outgoing air moves toward the outside and that the cooling only functions with a running fan.
The task of the present invention is to make possible a purposeful and effective cooling of the engine block, particularly the areas which are at a critical temperature and are highly heated, in which all the cooling air fed by the blower can be used and which also displays its full effect in the common engine compartments of today's front-wheel-drive motor vehicles which are characterized by restricted space proportions and are open at the bottom.
According to the invention, the task is solved by a cooling device of the type described above, in that the axial-radial blower in a known manner is mounted between the radiator and the internal combustion engine and that an air collection housing is connected to the axial-radial blower with air output directed into the upper area of the engine compartment.
It is known from DE-OS No. 18 04 607 that the radiator is mounted on the suction side of the blower, i.e., the blower is mounted between the radiator and the internal combustion engine. However, in this known, but nongeneric cooling device, a partial amount of the outgoing air from the radiator is suctioned by the cooling blower through the engine compartment. Therefore, the cooling device according to DE-OS No. 18 04 607 cannot solve the task specifically set in the present application.